Dual-Use Filter

The dual-use-filter policy checks content against dual-use terms. If blocked_terms is missing, the gateway uses a built-in list. This term check does not determine an item's export classification or legal status.

Configuration

pack:
  name: dual-use-filter-example
  version: 1.0.0
  enabled: true

policies:
  chain:
    - dual-use-filter

policy:
  dual-use-filter:
    blocked_terms:
      - centrifuge
      - precursor chemical
      - maraging steel
      - uranium enrichment
    action: block
    fuzzy_matching: true
    max_distance: 2

Fields

Field	Type	Description	Default
blocked_terms	string[]	Terms to match. If not supplied, the gateway uses its built-in reference list.	built-in list
action	block | redact	block stops the request. redact starts the gateway redaction path.	block
fuzzy_matching	boolean	Enable near-match detection.	false
max_distance	integer	Maximum edit distance used with fuzzy matching.	1

Built-in reference terms

The default list includes a broad starter set such as:

• weapon
• explosive
• bioweapon
• nerve agent
• dual-use / dual use
• nato restricted, nato confidential, nato secret
• precursor chemical
• cyber surveillance
• intrusion software
• nuclear material
• centrifuge
• uranium enrichment
• plutonium
• heavy water
• maraging steel
• carbon fibre / carbon fiber

Use cases

Block with custom terms

pack:
  name: export-control
  version: 1.0.0
  enabled: true

policies:
  chain:
    - dual-use-filter
    - entity-list-filter
    - itar-ear-filter

policy:
  dual-use-filter:
    blocked_terms:
      - uranium hexafluoride
      - thermal imaging
      - night vision
    action: block

Use the built-in defaults

pack:
  name: default-dual-use-guard
  version: 1.0.0
  enabled: true

policies:
  chain:
    - dual-use-filter

policy:
  dual-use-filter: {}

How it works

1. Verdictan makes one text buffer from the input message content.
2. It loads blocked_terms, or the built-in reference list when blocked_terms is not supplied.
3. It checks for specified matches without case sensitivity.
4. It can also examine fuzzy matches at max_distance or less.
5. On a match, it returns the action verdict.

Best practices

• Keep blocked_terms narrow when you override the defaults.
• Use block when deterministic enforcement of the matched term is necessary.
• The redact verdict uses the gateway redaction path. This policy does not give a special replacement marker.
• Combine it with other term controls only as a signal layer. Complete the necessary export-control review external to this policy.

Next steps

• Entity List Filter — configured entity-name matching
• ITAR/EAR Filter — Export-control term blocking
• Embedding Detector — Similarity-based matching
• DLP Filter — Custom regex and term controls